Use the type of the store for the byteswap, not the type of the
store's value argument.
Normally when we're storing a 16-bit value, the value being stored is
also typed as 16 bits. But sometimes it is typed as something smaller,
usually because it is the result of an upcast from a smaller value,
and that upcast needs no instructions.
If the type of the store's arg is thinner than the type being stored,
and the byteswap'd value uses that thinner type, and the byteswap'd
value needs to be spilled & restored, that spill/restore happens using
the thinner type, which causes us to lose some of the top bits of the
value.
Fixes#59373
Change-Id: If6ce1e8a76f18bf8e9d79871b6caa438bc3cce4d
Reviewed-on: https://go-review.googlesource.com/c/go/+/481395
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/483177
Auto-Submit: Dmitri Shuralyov <dmitshur@google.com>
The test directory contains tests of the Go tool chain and runtime.
It includes black box tests, regression tests, and error output tests.
They are run as part of all.bash.
To run just these tests, execute:
../bin/go run run.go
To run just tests from specified files in this directory, execute:
../bin/go run run.go -- file1.go file2.go ...
Standard library tests should be written as regular Go tests in the appropriate package.
The tool chain and runtime also have regular Go tests in their packages.
The main reasons to add a new test to this directory are:
it is most naturally expressed using the test runner; or
it is also applicable to gccgo and other Go tool chains.
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